Showing papers on "Oxalic acid published in 1974"

Relations between oxalic acid, calcium, magnesium and creatinine excretion in normal men and male patients with calcium oxalate kidney stones.

Abstract: 1. The daily excretion of oxalate, calcium, magnesium and creatinine was determined in fifty-two normal men and sixty-five male patients with calcium oxalate-containing renal stones. 2. Direct relationships were found between calcium and oxalate excretion, magnesium and oxalate excretion and calcium and magnesium excretion in both normal subjects and stone-formers. The significance of these relationships is discussed. 3. The mean excretion of calcium and oxalate was significantly higher in the stone-formers, compared with the controls, both calcium and oxalate excretion being raised by about 20%. 4. The effect of oral ingestion of glucose and casein on the rate of excretion of calcium, magnesium, oxalate and phosphate was examined. Glucose increased the rate of calcium and magnesium excretion but had no effect on oxalate excretion and suppressed phosphate excretion. Casein also increased calcium excretion but had little or no effect on magnesium or oxalate excretion, and it increased phosphate excretion. 5. The association of high calcium excretion with high oxalate excretion, in both normal subjects and stone-formers, results in a high degree of supersaturation of the urine with respect to calcium oxalate. The implication of these findings with respect to the cause and treatment of calcium oxalate stones is discussed.

A study of the production of glyoxylic acid by the electrochemical reduction of oxalic acid solutions

Abstract: An investigation has been made of the formation of glyoxylic acid by the electrochemical reduction of oxalic acid/sulphuric acid aqueous solutions at various temperatures and cathode potentials using lead electrodes. It has been found that for a given quantity of electricity passed greater current efficiencies are obtained at higher electrode potentials and lower temperatures. The current efficiency decreased with increasing quantity of electricity passed. A simple analysis for the process has been made in which glyoxylic acid is assumed to be reduced to glycollic acid. By incorporation of a variable factorf, to take into account electrochemical parameters for the two reactions, satisfactory predictions of the current efficiency have been obtained. The electrokinetic interpretation of thef-factor is also briefly discussed.

Biomolecules from HCN

Abstract: The mechanism of the condensation of dilute aqueous solutions of HCN and the products formed by these reactions have been investigated. The initial HCN condensation reactions yield3, a compound which is readily oxidized to4. A similar oxidation of5 to6 was also observed. Urea is formed on hydrolysis of4. The oxidation-reduction products formed from HCN may be in part a consequence of the oxidation of3. It has been established by combination GC/MS that the amino acids glycine, diaminosuccinic acid, α-amino-isobutyric acid, aspartic acid, alanine and isoleucine are released on acid hydrolysis of the ‘HCN polymer’. Hydantoin (7), 5,5-dimethylhydantoin (8) and 5-carboxymethyldenehydantoin (10) are also released on acid hydrolysis of the HCN condensation products. The direct conversion of the dicarbonyl derivative, of diaminosuccinic acid to orotic acid via10 at pH 8 has been observed. This conversion suggests a direct route to pyrimidines from HCN.

Three-electron oxidations. VI. Chromic acid cooxidation of cyclobutanol and oxalic acid. Chromium(V) oxidation of cyclobutanol

Abstract: The chromic acid cooxidation of cyclobutanol and oxalic acid yields only cyclobutanone and carbon dioxide with the CO/sub 2/: cyclobutanone ratio varying from 1: 1 to 4: 1 depending on the initial ratio of the two substrates. The chromic acid oxidation in the presence of oxalic acid thus provides a quantitative method of converting cyclobutanol to cyclobutanone with complete suppression of ring cleavage side reactions. The chromium(V) oxidation of cyclobutanol yields cyclobutanone. The deuterium isotope effect of the reaction is k/sub H//k/sub D/ = 4.96. Cyclobutanol is only 2.3 times more reactive toward chromium(V) than isopropyl alcohol. A mechanism for the chromium (V) oxidation is proposed which is analogous to the mechanism of the chromium(VI) oxidation of alcohols and involves reversible formation of an ester intermediate and carbon- hydrogen bond cleavage in the rate-limiting step. The presence of either acrylonitrile or acrylamide leads to polymer formation during the oxidation; however, with acrylonitrile, a constant 1: 1 ratio of cyclobutanone: carbon dioxide is formed, whereas in the presence of acrylamide, the ratio of the two products is a function of the initial concentration of the substrates. The difference between the two monomers is interpreted in terms of different reactivity of themore » polymer radical toward oxidation. All results obtained in this study are fully consistent with the earlier proposed three-electron mechanism for the cooxidation reaction. (auth)« less

Routine micromethod for determination of oxalic acid in urine by atomic absorption spectrophotometry.

Abstract: The method of Gitelson et al. was modified to a microscale procedure and adapted for atomic absorption spectrophotometry. Oxalic acid in urine is precipitated with excess of calcium ions at pH 5. The excess of calcium present in the supernate and the total calcium added and present in the urine at pH 2 are determined by atomic absorption spectrophotometry. The oxalic acid present in the precipitate is calculated indirectly from the difference between the two determinations of calcium. This method is useful for routine determination of urinary oxalic acid.

Enzymatic assays for glucose, creatine phosphokinase or plasma ammonia

Abstract: Enzymatic assays for determining glucose, creatine phosphokinase or plasma ammonia, wherein nicotinamide adenine dinucleotide is reduced or the reduced form of nicotinamide adenine dinucleotide is oxidized to nicotinamide adenine dinucleotide, are carried out in the presence of about 2 to 50 micromoles per liter of oxalic acid or oxamic acid, or salts thereof The oxalic acid, oxamic acid and salts thereof inhibit lactic dehydrogenase which causes errors in the assays

Influence of light intensity, fertilizers and salinity on oxalate and mineral concentration of two vegetables (Chenopodium album L. and Chenopodium amaranthicolor L.)

Abstract: The effect of light intensity on the synthesis of oxalate and cation concentration in leaves, stems and roots ofC. amaranthicolor L. was investigated. It appears that oxalic acid is synthesized in leaves from metabolites of both photosynthetic and non-photosynthetic origin. In roots the effect of light on the oxalic acid synthesis was different to that of leaves and stems. Cation uptake seems to increase with increase in oxalic acid production.

Catalyst of supported vanadium oxide and manganese oxide and method of producing same

Abstract: The catalyst for selective removal of nitrogen oxides from waste gases is actually vanadium oxide and manganese oxide applied to an inert carrier. Said metal oxides are taken in the weight ratio V 2 O 5 /Mn 2 O 3 of 0.1 - 30:1, the total weight of the metal oxides being 5 - 40 per cent of the total weight of the catalyst. The proposed catalyst is prepared by dissolving ammonium metavanadate or vanadium pentoxide in an aqueous solution of oxalic acid having a concentration of 10 to 360 g/liter. A hydro-soluble salt of manganese is then dissolved in the obtained solution of ammonium oxalate-vanadate or oxalate-vanadic acid, the manganese salt being taken in such a quantity that the weight ratio of ammonium oxalate-vanadium or oxalate-vanadic acid to the manganese salt should be from 0.1 to 30:1 calculating with reference to the ratio of the metal oxides V 2 O 5 /Mn 2 O 3 . The thus-prepared solution is used to impregnate an inert carrier, which is then dried at a temperature of 110° - 120° C, and calcined at a temperature from 400° to 600° C. Said operations of impregnating, drying, and calcining are performed at least once.

Process for preparing higher purity azo compounds

Abstract: After an azonitrile is prepared by coupling an aminonitrile in the presence of a hypochlorite, the reaction mixture is acidified to a pH of 4 or less and an alkali metal, alkaline earth metal or quaternary ammonium nitrite, sulfite, bisulfite or thiosulfate, sulfur dioxide, nitrogen oxide, oxalic acid, formaldehyde or hydroxylamine is added as a reducing agent.

Surface treatment of aluminium and aluminium alloys

Abstract: The surface of aluminium or an aluminium alloy is treated by electrolytic deposition of a copper-indium alloy surface layer followed by the diffusion heat treatment of the coated surface. Electrolysis is carried out in a bath containing, in an aqueous alkaline solution, monovalent copper ions, trivalent indium ions, an alkali metal hydroxide, an alkali metal cyanide, an alkali metal gluconate, gluconic acid, and oxalic acid, and the heat treatment is carried out at between 120* and 155*C.

Studies on the Chemical Compositions of Citrus junos in Korea

Abstract: The chemical components of Citrus junos produced in Korea were divided into two parts; common and special components respectively. In the former the relation between the physiological effects of the plant and its ripening process was observed periodically while the latter was analyzed the ripening fruits for their effective utilization as food. The results are summarized as follows: 1. The analytical result of seasonal change showed that the rind ratio was higher than the flesh ratio and on a regional basis, the rind ratio was higher in the islands than on land areas. 2. In the experiment the moisture was increased until the third period, but afterwards it was made constant. While the content of crude fat, cellulose, ash, total acid and soluble non-nitrogen material were decreased until the third period and the cotent of cellulose and total acid were continuousely redused until the last period. In con trast with the above the content of reducing sugars was increased but the content of crude fat, cellulose, ash, crude protein and soluble non-nitrogen material were increased until last period. 3. The content of vitamin C was richer in the rind than in the flesh, in the Korean species than in the Japanese. 4. Free sugars; xylose, fructose, glucose were richer in the rind than in the flesh. 5. The content of volatile organic acids was richer in the rind than in the flesh. Among them, volatile acids, acetic acid, formic and n-valeric acid were found in the rind and formic acid, acetic acid and propionic acid were deteceed in the flesh. 6. The total content of non-volatile acids was richer in the flesh than in the rind. In the kind of non-volatile acids, citric acid,glutaric acid, malic acid, tartaric acid, oxalic acid, malonic acid, succinic acid and an unknown acid were found in the rind and citric acid, malic acid, succinic acid, oxalic acid, glutaric acid and malonic acid in the flesh. 7. Three kinds of aromatic components: D-limonene, , p-cymene and seven other kinds of unknown aromatic components were detected in neutral essential oils. Among them, D-limonene seemed to be main aromatic component in the fruits. 8. From the above results it is confirmed that both rind and flesh of the ripened fruit could be utilized for food effectively, and unripened fruits are suitable for producing citric acid, ripened fruits are also useful for producing juice.

Solvent extraction of niobium and tantalum: IX. Extraction with di-n-octylamino butanone-(2) and di-n-octylamino acetic acid

Abstract: The extraction of niobium and tantalum from hydrofluoric and oxalic acid solutions by di-n-octylamino butanone-(2) [DOAB]and by di-n-octylamino acetic acid [DOAA]has been studied, together with its dependence on the ligand and hydrofluoric acid concentrations. The species of niobium and tantalum extracted with DOAB have been isolated and characterized by analysis and i.r. spectra. I.r. spectra of the ligands as well as of the extracted species dissolved in the organic phase, were compared with the spectra of the separate substances. The complexes (DOABH)3(MeO(C2O4)3), (Me = Nb, Ta) have been isolated from oxalic acid solutions. From 0.04 M HF solutions, the species isolated correspond to the formulae (DOABH)2 · NbOF5 and (DOABH) · TaOF4 for niobium and tantalum, respectively. In higher concentrations of hydrofluoric acid the formation of the complexes (DOABH)2 · NbOF5 and (DOABH)2 · TaF7 can be deduced.

The Oxalic Acid Content of Vegetable Foods

Abstract: 1) 植物性食品中の蓚酸含量をBergermanとElliotのインドール比色法で測定した。この結果蓚酸を多く含んでいるもので無水物として1%以上にアカザ, ツルナ, 煎茶, 1～0.5%にホウレンソウ, ショウガ根, フダンソウ, タケノコ, ハマボウフウ, ミョウガ, イタドリがあった。2) ミツバについては2月の市販温室物で微量であったが, 8月の採取品では総蓚酸0.135%と多くなっていた。3) コンニャクイモ, タケノコにも多いが, 市販コンニャクでは0, タケノコ水煮缶では0.165%と少なかった。4) キノコ類4種では少なかった。5) イモ類は0.1%前後の蓚酸を含んでいた。6) 以上は生の食品中の蓚酸で, これは調理加工によりかなり除くことができるので, 多いものはゆでたり水にさらすと摂取時にはかなり少なくすることができる。

The decomposition of acetylenedicarboxylic acid in acetophenone

Abstract: The decomposition of acetylenedicarboxylic acid in acetophenone was studied in the temperature range of 100–130°C. The rate constants and activation parameters for the consecutive pair of first-order steps (each yielding carbon dioxide) were calculated. Hydrogen kinetic isotope effects were also studied. Comparisons were made with the decompositions of oxalic acid and malonic acid. An intramolecular HC transfer is believed to be the main part of the reaction coordinate in addition to the CC bond breaking.

Anodisation and resin impregnation of aluminium profiles - for insulating carrier grooves for wire in magnetic memory stores

Abstract: Partial or complete coating by immersing parts made of (or coated with) Al alloys in 1-8% oxalic acid at is not >20 degrees C with a current density 20-100 mA/cm2, to give a uniform, strong, corrosion resistant insulating layer, the thickness being controlled by the oxidn. time. Pref. 5% oxalic acid is used at 18 degrees C, with current density 22.5 mA/cm2, after which the parts can be exposed to a phenol-formaldehyde vapour mixt. at 200 degrees C for 30 mins. to impregnate the pores of the insulation layer with resin, thereby improving the insulation and corrosion resistance and the mechanical strength. The coating is suitable for the general insulation of Al, partic. carrier grooves for wire memory stores.

Method for the reduction of zinc ion concentration and removal of organic impurities in a neutral or acidic, aqueous zinc plating bath

Abstract: A composition and method for the reduction of zinc ion concentration and removal of organic impurities in a neutral or acidic, aqueous zinc electroplating bath by adding directly to the bath ammonium oxalate, or the combination of oxalic acid and a stoichiometric amount of ammonium hydroxide.